A technique designed to reduce the amount of wood and waste in the construction of a wood-framed house. This also helps reduce the total cost of the construction or remodeling project. This technique allows more space for insulation, which helps the structure achieve better energy efficiency. By combining advanced framing techniques and using environmentally friendly building materials such as FSC certified woods, construction projects may achieve high level of sustainability, functionality and efficiency.

• On non-load-bearing walls, headers should not be used. A single stud is enough support for an opening or a door.
• Rather than sawn lumber, space floors with I-Joists and roof rafters up to 24 inches on center.
• Corners should use two-stud corner framing. Rather than four or more studs, use drywall clips or scrap lumber to connect the drywall.
• By using In-Line framing, floors, walls, and roofs line up with one another and therefore loads are transferred directly downward. This also helps the structure to become stronger and more stable.

Source: http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10090
These blocks are a mixture of cement, silica sand, lime, water, and aluminum powder. When mixed these materials create a reaction that causes very small hydrogen bubbles to form, which creates a fivefold increase in volume while trapping the air bubbles to create insulation. This block is then steam-cured in a pressurized chamber. This material is then cut into smaller blocks, which may be used for floors, roof panels, walls etc. Many builders prefer AAC blocks to other material because they provide fireproofing, insect resistance, mold proofing, and sound-absorption. They are also hypoallergenic and may be used in hurricane prone areas.

AAC blocks may provide an insulation of up to R-21 for 8 inches. The cost of AAC blocks is approximately $2.20 - $2.50 per square ft. Although comparable to the price of Concrete Masonry Units (CMU’s), labor may be less expensive since a crew of 4-6 people may install it. Also, when combined with the fact that it replaces many of the materials used in wood framing savings become more noticeable.

Structural Insulated Panels (SIP) are panels composed of a thick layer of foam (polystyrene or polyurethane) with a panel of oriented strand board, plywood, or fiber cement on each side. SIP’s may be used for floors, walls, and roofs. They are considered a very green product since it combines two products in one - insulation and structure- and substantially reduces the length of time that building materials are exposed to the weather. SIP’s provide a very good level of insulation and better thermal performance than traditional framing methods. They also provide good sound absorption. Although termites don’t feed on these panels, there is a chance they may nest inside them. To prevent termite nests, builders may place a steel mesh barrier and some manufacturers offer borate-treated panels.

Although SIP’s are produced in standard sizes, clients can request custom-sized panels to fit the structure’s needs. Panels are commonly found to be 4 to 25 ft wide, 8 to 10 ft high, and thicknesses of 4 to 6½ inches. Roof panels may be found with thicknesses of up to 12 inches. The cost of implementing SIP’s into a project is close to that of standard framing techniques. Nevertheless, there is a premium cost for custom-sized panels.

• Plumbing and electrical cable channels must be predetermined so that the manufacturer may accommodate the chases inside the foam.
• Store the panels under cover; out of the sun and off the ground.
• Use borate-treated panels or steel mesh barriers to prevent insects from burrowing into the foam.
• Ensure the panels provide the right level of insulation for your area.

This product is made from young, small diameter trees and scrap wood that is then reassembled into different wood veneers and strands. All the pieces of wood are coated with adhesives under heat and pressure and sawn into standard dimensions. The following products fall into the engineered lumber category: I-joists, Oriented Strand Board, Glue-laminated lumber, Laminated veneer lumber, Oriented Strand Lumber, and Plywood. It is important to avoid using products with urea formaldehyde glues. Urea is water-soluble glue used for indoor products. This may off-gas formaldehyde for up to 5 years, creating a poor indoor air quality. For healthier results, use water-resistant formaldehyde-free methylene-diisocyanate (MDI).

The cost for engineered lumber, although more stable than dimensional lumber, may be 3 to 4 times higher.

Steel studs are very common materials among builders. Although not considered the greenest product it may have some environmental attributes. Builders may use steel studs made out of recycled steel containing FSC certified or reclaimed wood on each end for attaching purposes. On the downside, steel studs are an excellent heat conductor, which reduces a structure’s energy efficiency.